SDL : Hardware rendering vs Software rendering

Question

A general question about a window with an extensive menu that is updated often , but only around 10% of the actual screen is updated. Much if the text remains unchanged.

SDL2 uses rendering and textures to utilize hardware acceleration , but is also allows software rendering.

My question is:

• Is it faster to redraw the entire screen/menu each time by rendering directly to the hardware using SDL_CreateRender() / hardware-render where the entire menu is drawn each time when only 10% of the menu actually changes ? Or:
• Is it faster to write the entire menu once into RAM using SDL_CreateSoftwareRenderer() / software-render and then update only the 10% that actually changes?

Answer 1

Thanks guys.

It is nice to be able to get other opinions before spending a lot of time on an issue. The simplest route was to use hardware rendering and redraw the entire window each time as it is fast enough.

The main program draws everything (real-time data and GUI under Linux ) as individual pixels to a texture which is rendered at a 30Hz rate to the screen. What I found was that once CPU clock rates exceeded 1Ghz , most of the graphics ( small areas / pixels) was as fast or faster than hardware rendering , except when clearing a large area of the screen..It took some work and a lot of reading to get the SDL rendering working in a thread while the pixel data (GUI and data ) is being updated in main.